Devices for coupling two members together are well known. Many of these devices allow members to be coupled and adjusted to a desired position. However, existing devices suffer from many disadvantages wherein it is difficult to engage and disengage the coupler. For example, in some existing devices the coupler must be physically pressed to lock or unlock the coupler. In addition, when pressing the coupling device to engage or disengage, existing devices tend to bind. Therefore, a device has been needed which couples two members together, allows the coupler to be easily engaged and disengaged and does not bind.
U.S. Pat. No. 6,032,555 issued to Lowell Blake Whitley (Whitley) on Mar. 7, 2000, discloses one such solution wherein an indexable ratchet wrench has a splined pin that couples the ratchet head to the handle and includes a plurality of spline members moveable in the plane of the handle and ratchet head in response to rotation of an actuator. The spline members are spring loaded to a retracted position. Each spline member includes a camming surface which engages a cam lobe formed on the actuator. As the actuator is rotated about the axis of the splined pin, the cam lobes force the spline members radially outwardly from the axis of the splined pin to an engaged position. Unfortunately, the cam will eventually experience wear and provide only limited and weakened engagement of the spline members with the splined apertures. Additionally the plurality of moving parts linked by a spring makes the tool susceptible to jamming and misalignment.
A distinct advantage would be achieved by producing a coupler with a spring loaded splined pin using a minimum number of moving parts. It would be especially advantageous to produce a coupler which eliminates the need for cam lobes, which are susceptible to wear. This design would facilitate a longer and a more useful life span of the tool.